1. Field of the Invention
The present invention relates to a dye for a photoelectric device and a photoelectric device comprising the same. More particularly, the present invention relates to a novel dye for a photoelectric device showing improved energy conversion efficiency by incorporating different quaternary ammoniums into a bipyridyl ligand of the existing dye, and a photoelectric device comprising the same.
2. Description of the Related Art
In order to solve recent energy problems, extensive research on alternative energy resources that are capable of replacing existing fossil fuels is actively underway. In particular, to replace oil resources that are doomed to be exhausted within several decades, various attempts have been made to develop schemes for utilizing natural energy resources such as wind force, nuclear energy, solar energy, and the like.
Among these, a solar cell, which is a photoelectric device capable of converting solar energy into electric energy, is unlimited and environmentally favorable differently from any other resources, so it has been in the spotlight since the silicon solar cell was developed in 1983. Solar cells may be made of several types of raw materials, but of the possible materials, a solar cell based on silicon is most popular in the market. However, silicon solar cells have several problems in that it is hard to put to them to practicable use because production costs are very expensive, and improving energy conversion efficiency has proven difficult. Accordingly, in order to overcome these problems of the existing solar cells, the development of a dye-sensitized solar cell that can be fabricated at extremely low cost has been considered.
Unlike the silicon solar cell, the dye-sensitized solar cell is a photoelectrochemical solar cell that comprises, as its main ingredients, a photosensitive dye molecule capable of generating an electron-hole pair by absorbing visible light, and a transition metal oxide layer delivering the generated electrons. Since its production cost per unit of electric power is significantly low when compared with the existing silicon solar cell, the dye-sensitized solar cell has been receiving a great deal of attention as there is a possibility that it may prove useful as a substitute for existing solar cells.
Among the ingredients constituting the dye-sensitized solar cell, the dye molecule functions to generate excited-state electrons by absorbing visible light, and produces electromotive force by injecting the excited-state electrons into the conduction band of the transition metal oxide layer, and therefore the dye plays a very important role in the fabrication of a high-performance solar cell. Thus, there is an urgent need to develop a dye showing superior photosensitivity and improved light absorption efficiency, and therefore there is a great deal of interest in the development of such a new dye.